Boring type mining head having wedge means



July 3, 1956 c. H. BROWN BORING TYPE MINING HEAD HAVING WEDGE MEANS Filed May 1o, 1954 2 Sheets-Sheet 1l 1N VENTOR ATTORNEY July 3, 1956 c. H. BROWN 2,753,167

BORING TYPE MINING HEAD HAVING WEDGE MEANS Filed May 1o, 1954 2 sheets-sheet 2 l 26 l, A\

,g INVENTOR laremcebfrown ATTORNEY United States Patent() BlRlNG TYPE MINING HEAD HAVING WEDGE MEANS Clarence H. Brown, Chicago, Ill., assignor to Goodman Manufacturing Company, Chicago, Ill., a corporation of Illinois Application May 10, 1954, Serial No. 428,669

3 Claims. (Cl. 262--7) This invention relates to mining machines of the boring type and in particular to an improvement in the disposition of the boring arm assembly by reason of a specific arrangement thereof to provide improved clearance to wedge oi the cores of the material being mined.

In mining machines of the boring type there is usually disposed at least two boring heads, each having a plurality of arms with forwardly projecting cutter bits and arranged with their arms in side-by-side overlapping relation to cut two contiguous bores. Also mining machines of this general type are usually further provided with horizontally disposed cutter chains or other auxiliary cutting devices at the oor and roof to smooth off the triangular cores left between the adjacent boring head so that the resulting bore is generally oval in cross-section.

In mining machines of the general type as described above it is customary to provide each of the boring head assemblies with a center bit and a plurality of radially extending boring arms carrying cutter bit supports having cutter bits thereon.

The resulting cut of each boring head assembly is a plurality of circular kerfs concentric to a center bore cut by the center bit. However, the radial thickness of each kerf is substantially smaller than the radial thickness of the core of the material being cut which has been left between the kerfs and much diculty is had in providing clearance for this core material left by the cut to be wedged off and freed from the face.

lt has long been a problem in the mining industry that when the cutter support on the boring arms have been disposed in a radial line that there is no clearance for the core of the mined material to be wedged free from the materials face. When these cutter bit supports are disposed in a radial line the mined material is crushed and a great percentage of nes is recovered rather than chunks or lumps. Accordingly, it has been found that by the specific arrangement and disposition of the cutter bit supports carrying the cutter bits thereon as laterally offset to the radial axis of the cutter arm and laterally offset to each other will provide sutiicient clearance by reason of the radially outer kerf being formed circumferentially ahead of the core which is formed by the next radially inwardly adjacent kerf and the core between these kerfs will be wedged into the radially outward kerf.

lt is therefore a primary object of this invention to provide a clearance for the material being mined so that the core material may be wedged-oif from the main body thereof providing for more efcient and economical operation of the mining machine.

Other objects and advantages will appear from time to time as the following description proceeds.

The invention may best be understood by reference to the accompanying drawings, in which:

Fig. l is an elevational View of the head of the mining machine showing the invention in association with the other elements thereof;

Fig. 2 is a section along lines 2-2 of Fig. 1 and show- Patented July 3, 1956 ice ing the offset relation of the cutter bit supports on a boring arm assembly;

Fig. 3 is a section along line 3-3 of Fig. l showing the wedging of a core by a cutter bit support into the radially outwardly adjacent kerf.

Referring to the details of the embodiment of my invention illustrated in the drawings, there is shown in Fig. l a mining machine indicated generally at 10 having two boring heads 12 arranged in side-by-side relation with each other with the boring arms 14 rotating in over lapping non-interfering relation thereon.

It will be understood that the boring heads may have only two boring arms arranged diametrically from each other. lt is to be noted that the boring arms 14 are carried on the mining machine 10 at equally spaced angles from each other. Further, there is provided radially inwardly on each boring arm 14 a forwardly projecting cutter bit support 16, each cutter bit support carrying a plurality of cutter bits 18 along the outer ends thereof in the usual and accepted manner for cutting a circular kerf in the face of the material being mined. Further the outermost end of each arm 14- is provided with a forwardly projecting cutter bit support 20, similar to the support i6, and carrying thereon cutter bits 22 for cutting the outer kerf. Also, intermediate the supports i6 and 20 there is provided a cutter bits support 24 which projects forwardly and is similar to the supports 16 and Ztl. Intermediate support 2d carries thereon cutter bits 26 for cutting the intermediate kerf in the: material being mined. There may also be provided scoop plates 28 mounted on the end of each arm 14. A center bit 30, tapered near its inner end, projects from the front end of each boring head at the hub of the arms 14, and since the cutter bit supports, scoop plates and the center bit are all well known in the art they need not be more fully described and form no part of the present invention.

For the purpose of brevity only a single boring arm M will serve as illustrating my invention, and accordingly further reference shall be made to such single arm. Referring now to the subject matter of my invention, namely a means for providing an improved clearance to wedge oli the cores of the material being mined, attention is directed to Fig. 2, wherein it will be noted that the outermost cutter bit support 20 is circumferentially or laterally oiset in the direction of rotation of the boring head forward from the intermediate cutter bit support 24 and the inner cutter support 16. Further, the intermediate cutter bit support 24 is circumferentially or laterally offset in the direction of rotation of the boring head l2 forward of the innermost bit support 16 and rearward of the outermost bit support 20. Further, the innermost cutter bit support 16 is circumferentially or laterally offset in the direction of rotation of the boring head 12 rearward of both the intermediate support 24 and outer support 20. In addition, you will note that the innermost cutter bit support 16 is disposed in the direction of movement of the mining machine forward of both the intermediate cutter bit support 24 and outer cutter bit support 2t). Further, the intermediate support 24 is disposed in the direction of movement of the miningl machine rearward of the inner support 16 and forward of the outer support 2t). Also, the outer support 2t) is disposed in relation to the movement of the mining machine rearward of both the inner support 16 and intermediate support 24. j

This specific disposition of the cutter bit supports 16, 20 and 24 provides a clearance which is in fact the kerfs cut by the cutter bits 18, 22 and 26.

Attention is now directed to Fig. 3 wherein there is shown a kerf 32 of the outermost cutter support 2t) and it is readily seen that the core 34 of the :material being mined is wedged radially outwardly by the speciiic wedge configuration 36 of the intermediate support 24, and this mined material 34 has a clearance or opening into which it may be wedged and severed from its face. The cross sectional wedge configuration of the innermost support 16 is similar to that shown in Figure 3 of the wedge con figuration 36 of the intermediate cutter bit support 201, but by reason of the specific cross-seetional view of Fig. 3 the innermost kcrf has not been cut and accordingly, it is not shown.

it is to be readily understood that by the specific disposition of these cutter bit supports 16J 2t? and 1M, which in turn carry thereon the cutter bits 13, 22 and Z6 respectively provide for an improved clearance wherein the cores cut intermediate each kerf may be wedged into the Vradially outer korf and thus easily severed from the mined materials face.

Although i have shown and described certain embodiments of my invention, it will be understood that I do not wish. to be limited to the exact construction shown and described, but that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims,

i claim:

l. in a mining machine of the boring type having a radially extending rotating boring arm carrying a plurslty of cutter bit supports thereon, said supports being cireumferentially offset on said arm with each radially adjacent pair of said supports being disposed with the radial outer support thereof offset in the direction of re .tion of said arm forward of the next adjacent radial inner support, each radial inner support having a wedge portion disposed in the direction of rotation of said arm rearwardly of each radial outer support, whereby a kerf will be eut by each outer support cireumferentially forward of a kerf Cut by each radial inner support providing a clearance for a core of material intermediate the kerfs to be wedged radially outwardly into the radial outer kerf by each radial inner support during the operation of the machine.

2. The structure defined in claim 1, wherein said wedge portion is defined by each inner support being tapered from a maximum radiall thickness on the circumferential rearward portion to a minimum radial thickness on the circumferential leading portion and from a maximum radial thickness on the axial rearward portion to a minimum radial thickness on the axial forward portion.

3. In a mining machine of the boring type having a radially extending rotating boring arm carrying a plurality of cutter bit supports thereon, said supports being eircumferentially offset on said arm with each radially adjacent pair of said supports being disposed with the radial outer support thereof offset in the direction of rotation of said arm forward of the next adjacent radial inner support, each radial inner support being tapered from a maximum radial thickness on the circumferential rearward portion to a minimum radial thickness on the circumferential leading portion and from a maximum radial thickness on the axial rearward portion to a minimum radial thickness on the axial forward portion defining a wedge portion offset in the direction of rotation of said arm circumferentially rearwardly of each radial outer support.

References Cited in the le of this patent UNITED STATES PATENTS 476,836 Stanley lune 14, 1892 1,326,455()` Dana Dec. 30, 1919 1,603,621 McKinlay Oct. 19, 1926 

